Recent Posts

Pages: [1] 2 3 ... 10
1
This probably has a name, but can't really pin it!

I have a traditional cheap sine/triangle/square 12M or so signal generator. It has sweep etc. but it does not have a setting that I can simply send out exact amount of pulses.

There must be a simple product somewhere?

I can see very complicated arbitary signal signal generators that can produce all sorts of serial communication protocols etc. some even tempting cheap, but they need laptop and to learn a new scripting language and all that extra.

I remember when I was studying we had all that lab equipment that would do stuff and we could use simple counter/pre scaler with gate-function to count the pulses from generator and gate some multiples of ten out.

Could cobble out arduino stuff....but I see myself on doing this increasingly offten and I', looking at the signal generator trigger and TTL BNC connectors and thinkking one more little box....even if I have to solder together some eBay specials.

Now my needs are modest:
* TTL-level input/output, a little of overvoltage/negative voltage protection or buffer on socet would be nice
* Modest speed, generally 100 kHz or so would be most of the time enough
* Amount of pulses random: one to least 2k
* own simple TTL pulse generator plus, but I have one that has two output PWM, phase angle and all that.


I checkked the manual of my generator and it does not provide this simpply. Apparently I could learn another scripting language, do it on PC, hook it up on my signal generator and play it out....but I am such a old timer that I rather not.

Pekka
2
New from Old / Re: Rebirth of a Denford MIRAC CNC Lathe
« Last post by awemawson on Today at 02:52:48 AM »
The registration form requires, iirc, a product number / serial number and if not completed you cannot proceed.  :bang:

I wanted to know basic things about the PC such as how much memory, what sort of disk drive etc and also dimensions of it and the touch monitor along with mounting details. Basic details to see if it would fit ! I'd have expected such detail to be on their web site but couldn't find it so asked if it was there somewhere

But no reply so no purchase  :scratch:
3
CNC / Re: DDCSV1.1 4 Axis controller
« Last post by WeldingRod on February 18, 2018, 10:00:28 PM »
 :mmr:
OK, I went and tested the functions that JPoepsel found.  All I can say is SCORE!
All of this is with this preface code: G17 G21 G90 G94 G54.  Thus, I am expecting all of this to happen in the XY plane, which it does.

G12, G13, I is radius of the circle.  It starts with a +X motion to the radius, finishes at center
G102  Clockwise from the top, G103 is counterclockwise
   A; the ANGLE of the major axis.  0 degrees is aligned with Y
   45 is +x +y direction
   Center of the elipse is at start.  It goes back to the start position when it finishes.
G110 starts at current position, Goes +X and +y half the cutter, goes to Z position
    X is the X measure of the rectangle, starts toward +X
   steps toward +y by 1 cutter diameter each pass, goes back to start position afterwards
G111 Mills outward from center in circles, finishes at start position, with a radial step outward in the +X direction
   As an example, G111 I10 Z-10 R1 works
G112 is opposite rotation
   **** Works with R2 and R2.9, just does a stair step at R3 if the circle is only 30mm or so.  A really big circle will get you a stairstep outward, then a revolution or two.
   Has a hitch/jolt once per rev. as it steps outward
   Tool path display doesn't work right for this

G81 XYZ is the step over distance from the start point. K is the number of cycles. 
   Basically drills a set of holes in a line.  DOES NOT go back to start point
   R is drill depth

G82 P is pause, looks like milliseconds, Everything else the same as G81
G83  Q is distance per peck cycle, Everything else the same as G81.
   So, if you are drilling 10mm deep and set Q for 2mm, it will take 5 peck cycles to get to bottom.
4
New from Old / Re: Rebirth of a Denford MIRAC CNC Lathe
« Last post by DICKEYBIRD on February 18, 2018, 09:10:57 PM »
Couldn't ask a question on the forum as not yet a customer so couldn't register
WOW!  I'm completely flabbergasted by that Andrew.  There's a forum member that continually whinged about Acorn not doing this or that that he thought it should do who hasn't even purchased one so I can't fathom why someone like you has been denied registration.  Maybe the Centroid staff got tired of defending their product from non-owner back biters & now refuse admission unless one buys one...wko knows???  I do know that they've now sold a bunch of them & the support volume has increased.  They are a dedicated bunch of folks and work very hard to respond to their customers' questions.  I'm positive that a person such as yourself would be a welcome addition to the group, Acorn owner or not.

If there's something you need an answer to I'd be happy to ask it for you although it looks like you've just about made the original system your slave & may not want spend the money on a new control yet. 
5
New from Old / Re: Rebirth of a Denford MIRAC CNC Lathe
« Last post by awemawson on February 18, 2018, 04:56:48 PM »
I was all set to order not only the controller, but also the pre-loaded PC with Win10 and touch screen monitor. Couldn't find a spec on their web site for it. Couldn't ask a question on the forum as not yet a customer so couldn't register  :bang: So I sent an email and even now three weeks later haven't had a reply. So no, not bought the Acorn controller !

Meanwhile I have the original controller working quite nicely thank you and am working on replacing the internal PC and re-learning all I've forgotten about Dos 6.22  :lol:
6
New from Old / Re: Rebirth of a Denford MIRAC CNC Lathe
« Last post by Pete. on February 18, 2018, 03:27:30 PM »
Did you order the Acorn controller Andrew, or are you holding off to see what the original controller works like?

This guy seems to be having some trouble getting his order in:

http://bbs.homeshopmachinist.net/threads/75744-Any-news-on-the-Acorn-CNC-board
7
Electronics & IC Programing / Re: Ward indexer - Pololu DRV8825 Stepper Motor Driver
« Last post by chipenter on February 18, 2018, 11:17:02 AM »
Ive bought two TB6600 from Bangood no problems , but had a problem with Arduino megga board complained and they sent me a new one , just had to wait tree weeks for it .
8
Project Logs / DRO on milling machine
« Last post by NormanV on February 18, 2018, 11:16:31 AM »
I have a tendency to put off doing things, but today I got on with it and fitted a DRO on the Z axis of my home made milling machine. I have used the machine quite a lot since I completed it but have always found it frustrating that the Z axis had no scale on it. I knew that one turn of the handle moved the cutter 1/10th" but as I prefer to work in metric it was a darned nuisance. I had a spare 150mm digital caliper so I decided to modify it to do the job. I cut off all the pointy bits with my angle grinder and sharpened a carbide masonry drill bit to cut metal and that made the mounting hole at one end. A few minutes with the angle grinder on some square tube made the mounting bracket and three holes drilled and tapped in the castings of the mill and it was done! It only took thirty minutes, I am mad at myself for struggling with the machine for so long.
9
Our Shop / Re: Another machine joins the stable...
« Last post by awemawson on February 18, 2018, 07:14:48 AM »
Ade,

Glad to hear that it's an ongoing project and not abandoned  :thumbup:

New job in the UK or China ?
10
Electronics & IC Programing / Re: Ward indexer - Pololu DRV8825 Stepper Motor Driver
« Last post by PekkaNF on February 18, 2018, 04:45:41 AM »
Thank you Phil.

That is a problem I have to consider too.

I got a Chinese driver from the mail and proceed to test that one.

Tehnical spesification claims it's perfect:
https://www.banggood.com/TB6600-Upgraded-Version-32-Segments-4A-42V-5786-Stepper-Motor-Driver-p-981997.html?rmmds=search&cur_warehouse=CN

But when I cross referenced the spesicication and TB67S109AFTG data sheet I noticed that word "upgrade" is very missleading and they have kept overly optimistic TB6600 numbers there to attract noob buyers. I don't even go trough the mistakes, it's all lies.

Anyway I got it, hookes it up to 16VDC/7A PSU and signal generator. Motor is NEMA 17 1,7A 200 step model.

Motor sound sick, moved erratically and hardly any moment on any mode. Also the motor current was all over the wall.

The front cover DIP settings have something wrong, I don't think same settings produce differet current limit.

Also motor connection differes on PCB and cover.

Found that current sense resistors had cold solder on the other end and unsoldered from the other end. Also the capacitors were pretty much unsoldered.

Pretty sure it was completely untested.
Pages: [1] 2 3 ... 10